Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 798 individuals from 42 different populations of chum salmon (Oncorhynchus keta) were examined for mtDNA variation. Populations were sampled across the geographic range of the species, from mainland Japan around the Pacific Rim to the state of Washington in the United States. The entire D-loop region (approximately 1 kb) was sequenced for 16 individuals from representative populations. Subregions (approximately 200 nucleotides each) of the D-loop reported to be rapidly evolving in salmon were sequenced for another 29 individuals. Only 4 nucleotide variants were detected, and they occurred in only 4 individuals. Four coding regions of the mtDNA genome were also examined using restriction fragment analysis of products amplified via the polymerase chain reaction. Only one, the region coding for NADH dehydrogenase subunits 5 and 6, showed any variation at this level. The restriction enzyme AseI revealed a polymorphism where the frequency of haplotypes was correlated geographically. We surveyed all individuals for this polymorphism and documented a cline in frequency of the haplotypes around the Pacific Rim. There was a significant frequency difference between Japan and 3 other major geographic regions (Russia, Alaska/Yukon, and British Columbia/Washington) for the presence of the 2 haplotypes. This marker may prove useful in the identification of continent-of-origin for individual chum salmon caught in the open ocean.
Mol Mar Biol Biotechnol 1993 Dec
PMID:Low levels of intraspecific variation in the mitochondrial DNA of chum salmon (Oncorhynchus keta). 791 Jul 70

Gene translocations from the organelles to the nucleus are postulated by the endosymbiont hypothesis. We here report evidence for sequence insertions in the nuclear genomes of plants that are derived from noncoding regions of the mitochondrial genome. Fragments of mitochondrial group II introns are identified in the nuclear genomes of tobacco and a bean species. The duplicated intron sequences of 75-140 bp are derived from cis- and trans-splicing introns of genes encoding subunits 1 and 5 of the NADH dehydrogenase. The mitochondrial sequences are inserted in the vicinities of a lectin gene, different glucanase genes and a gene encoding a subunit of photosystem II. Sequence similarities between the nuclear and mitochondrial copies are in the range of 80 to 97%, suggesting recent transfer events that occurred in the basic glucanase genes before and in the lectin gene after the gene duplications in the evolution of the nuclear gene families. Overlapping regions of the same introns are in two instances also involved in intramitochondrial sequence duplications.
J Mol Evol 1994 Aug
PMID:Promiscuous mitochondrial group II intron sequences in plant nuclear genomes. 793 78

Cytochrome b-c1 complex (ubiquinol-cytochrome c reductase) of beef heart mitochondria has been crystallized. Crystals grown in capillary tubes diffracted X-rays from a laboratory source to a resolution of 7 A and synchrotron radiation to a resolution of 4.5 A in the presence of mother liquor. However, the movement of crystals in the mother liquor makes data collection very difficult. Removal of the mother liquor from the crystals causes severe loss of diffraction quality. To circumvent these difficulties we have recently developed a method for crystallization of the cytochrome b-c1 complex from a gel. The sizes, shapes and diffraction qualities of crystals grown in gel approach those of crystals obtained from liquid. Preliminary experiments on a Xuong-Hamlin area detector indicate that these crystals have the symmetry of a body centered tetragonal space group with cell constants a = b = 157 A, c = 590 A. Assuming eight cytochrome b-c1 complex dimers per unit cell, the crystals have a solvent content of 70% (v/v). Under reduced pressure the crystallization time is significantly decreased. Although crystals obtained under reduced pressure are generally smaller, the shorter crystallization time provides an opportunity to explore more crystallization conditions.
J Mol Biol 1994 Nov 04
PMID:Crystallization of mitochondrial cytochrome b-c1 complex from gel with or without reduced pressure. 796 99

Myocardial mitochondrial function after acute adriamycin exposure was compared in infant and adult mice. Heart mitochondrial were isolated 48 h after an intraperitoneal injection of adriamycin. Concentrations of adriamycin in serum and heart tissue were not significantly different between infant and adult mice. Oxygen consumption (state 3 respiration), and respiratory control ratio (RCR) were studied polarographically. Enzyme activities in the respiratory chain [succinate-cytochrome c reductase (SCCR), NADH-cytochrome c reductase (NCCR), cytochrome c oxidase (CCO)], and adenine nucleotide translocase (ANT) were assayed. After saline injection (control), no significant differences were detected in state 3 respiration, RCR, and enzyme activity of ANT between infant and adult mice. The respective enzyme activities of SCCR, NCCR, and CCO in adult mice were significantly lower than those in infant mice. After adriamycin injection in adult mice, there were significant decreases in state 3 respiration (using glutamate and malate as substrates from 239 +/- 25 to 160 +/- 50 nanoatom O2/min/mg protein), RCR (using glutamate and malate as substrates from 7.2 +/- 1.0 to 4.4 +/- 1.4), and enzyme activities of SCCR (from 279 +/- 30 to 178 +/- 28 nmol/min/mg protein) and NCCR (from 331 +/- 43 to 237 +/- 30 nmol/min/mg protein), but there were no significant changes in infant mice. No significant changes in enzyme activities of CCO and ANT were found in either infant or adult mice following the administration of adriamycin. In conclusion, adriamycin is less toxic on the myocardial mitochondrial function in infant mice than in adult mice.
J Mol Cell Cardiol 1994 Jul
PMID:Age-related acute adriamycin cardiotoxicity in mice. 796 58

The bloodstream forms of the protozoan parasite Trypanosoma brucei lack spectrally detectable cytochromes and satisfy energy requirements mainly by glycolysis. When infected blood is ingested by the tse-tse fly vector, the bloodstream form cells differentiate to procyclic forms that have fully functional mitochondria. Procyclic cells have cyanide-sensitive, cytochrome-mediated electron transport and the full complement of TCA cycle enzymes. The developmental regulation of the cytochrome c reductase complex was examined at the RNA and protein levels. RNase T1 protection studies and Northern blot analyses demonstrated that bloodstream and procyclic form cells constitutively expressed the genes for two nuclear encoded cytochrome c reductase subunits, cytochrome c1 and subunit 4. Polyadenylated transcripts of both genes were present in bloodstream form cells at up to 20% of the procyclic cell levels. These levels were significantly up-regulated sometime after the onset of differentiation to the procyclic form. Despite the presence of subunit mRNAs in bloodstream form cells, subunit proteins were not detected until the cells had been allowed to differentiate in vitro for 6 h. Procyclic cell levels of subunit proteins and holocytochromes were reached by 48 h. Our results suggest that cytochrome c reductase is developmentally regulated at multiple levels, some involving post-transcriptional mechanisms.
Mol Biochem Parasitol 1994 Jun
PMID:Developmental regulation of Trypanosoma brucei cytochrome c reductase during bloodstream to procyclic differentiation. 796 70

The effects of BRB-I-28 and its derivatives (GLG-V-13, SAZ-VII-22 and SAZ-VII-23), a novel group of antiarrhythmic agents, were investigated on the rat heart mitochondrial respiratory chain. The results indicate that BRB-I-28 and its derivatives have concentration-dependent inhibitory effects on NADH oxidase and NADH-CoQ reductase (complex I), but they have no significant effects on succinate oxidase, succinate dehydrogenase (complex II), CoQ-cytochrome c reductase (complex III), cytochrome c oxidase (complex IV), and NADH-K3Fe(CN)6 reductase. The site of inhibition of BRB-I-28 and its derivatives on the respiratory chain was localized between flavoprotein n (FPn) and CoQ, which is similar to the effect of rotenone and several other antiarrhythmic drugs such as amiodarone, propranolol, etc. BRB-I-28 and its derivatives also have significant inhibitory effects on mitochondrial ATPase activity as reported for other antiarrhythmic drugs such as amiodarone, propranolol, quinidine, and lidocaine. However, BRB-I-28 and its derivatives have no direct effects on sarcoplasmic reticulum Ca(2+)-ATPase activity. The inhibitory effects of BRB-I-28 and its derivatives on mitochondrial oxidative phosphorylation may result in the depletion of ATP. This effect, in combination with their effects on Na+,K(+)-ATPase, could possibly produce an increase in Ca2+ concentration in cytosol. This may be another mechanism by which these DHBCN derivatives produce an increase in systemic arterial blood pressure and contractile force of isolated cardiac muscle. On the other hand, inhibition on mitochondrial respiration may account for some of the potential toxic effects of these diheterabicyclo[3.3.1]nonane derivatives.
Res Commun Mol Pathol Pharmacol 1994 Aug
PMID:Effects of novel antiarrhythmic agents, BRB-I-28 and its derivatives, on the heart mitochondrial respiratory chain and sarcoplasmic reticulum Ca(2+)-ATPase. 799 64

Hepatic microsomal NADPH cytochrome c reductase from nonhuman primate (Macaca mulatta) has been purified 76 fold by the combination of anion exchange, affinity and molecular sieve chromatographies. The purified preparation had approximate molecular wt of 63 kDa and carried out NADPH oxidation, cytochrome c reduction, 2,6-dichlorophenol indophenol (DCIP) reduction and production of superoxide anions (O2-.). The enhancement in NADPH cytochrome c reductase catalyzed NADPH oxidation by metal chelators viz. ethylenediaminetetra-acetic acid (EDTA)-FeCl3 and diethylenetriaminepenta-acetic acid (DTPA)-FeCl3 was dramatically higher than the enhancement in the reduction of cytochrome c and DCIP. DTPA-FeCl3 was found to be more potent stimulator of NADPH oxidation as compared to EDTA-FeCl3, but both had similar potency as for reduction of cytochrome c and DCIP were concerned. Superoxide dismutase (SOD) decreased EDTA-FeCl3 enhanced reduction of cytochrome c by 15%, but had no effect on the NADPH oxidation and DCIP reduction, whereas it significantly enhanced DTPA-FeCl3 stimulated NADPH oxidation, decreased cytochrome c reduction by 8% and did not affect DCIP reduction. In addition, SOD almost completely blocked the NADPH cytochrome c reductase catalyzed superoxide anion production. The results demonstrate that like rodents and lagomorphs, the hepatic microsomal NADPH cytochrome c reductase in nonhuman primate, Macaca mulatta can carry out single electron reduction of molecular oxygen.
Biochem Mol Biol Int 1994 Jan
PMID:Purification and characterization of hepatic microsomal NADPH cytochrome c reductase from rhesus monkey (Macaca mulatta). 801 90

The mitochondrial iron-sulfur protein (also termed Rieske iron-sulfur protein) of cytochrome c reductase was purified from potato tubers and identified with heterologous antibodies. The sequences of the N-terminus of this 25 kDa protein and of an internal peptide were determined to design oligonucleotide mixtures for screening a cDNA library. One class of cDNA clones containing an open reading frame of 265 amino acids was isolated. The encoded protein contains the peptide sequences of the 25 kDa protein and shares about 50% sequence identity with the Rieske iron-sulfur proteins from fungi and around 43% with those from mammals. In vitro transcription and translation of the cDNA reveals that the iron-sulfur protein is made as a larger precursor of 30 kDa which is processed by the cytochrome c reductase/processing peptidase complex from potato. The processing product obtained after in vitro processing has the same size as the mature protein imported into isolated mitochondria. The presequence, which targets the protein to the organelle, is 53 amino acids long and has molecular features different from those found in presequences of fungal iron-sulfur proteins, which are processed in two steps. Our results indicate that, unlike in yeast and Neurospora, the presequence of the iron-sulfur protein from potato is removed by a single processing enzyme in one step.
Plant Mol Biol 1994 May
PMID:Molecular features, processing and import of the Rieske iron-sulfur protein from potato mitochondria. 801 75

We have characterized a wheat mitochondrial gene, designated nad7, capable of encoding a 394-amino acid subunit of the respiratory chain NADH dehydrogenase complex. It contains four introns possessing group II features and their positions differ from those in both the liverwort mitochondrial nad7 pseudogene and the nuclear gene encoding the homologous 49 kDa subunit of complex I in Neurospora. The derived amino acid sequence of the wheat nad7 gene is strongly conserved relative to its nuclear or organellar counterparts in other organisms. C-to-U type RNA editing, which is observed at 32 positions within the coding region of wheat nad7 transcripts, strengthens protein sequence similarity. RNA editing is also predicted to improve base-pairing within the domain V/VI regions of all four introns.
Mol Gen Genet 1994 Jul 08
PMID:The NADH dehydrogenase subunit 7 gene is interrupted by four group II introns in the wheat mitochondrial genome. 804 65

A new method for the isolation of peroxisomes from rat kidney cortex is described. The L fraction obtained according to Wattiaux-De Coninck et al. (1965) was layered on a discontinuous Nycodenz gradient (density = 1.15-1.21 g/ml) and then centrifuged in a fixed angle rotor for 45 min. at 136,000 g. On the basis of the morphological and biochemical analysis, the fraction recovered at the bottom of the tube was composed mainly by peroxisomes enriched in fatty acyl beta-oxidation system, whereas lower enrichment was found for other peroxisomal marker enzymes. Negligible contamination by mitochondria (marker enzyme cytochrome oxidase), lysosomes (marker enzyme acid phosphatase) and microsomes (marker enzyme NADPH cytochrome c reductase) was found.
Cell Mol Biol (Noisy-le-grand) 1994 Jun
PMID:A preparative method for isolation of peroxisomes from rat kidney. 806 67


<< Previous 1 2 3 4 5 6 7 8 9 10